The events or manifestations that give rise to safety concerns typically have a negative valence and lead to unexpected and unacceptable outcomes, with names that signify the severity of the outcomes (ranging from incidents via accidents to disasters). Since they have a negative valence the natural response is to try to avoid them, or at least to reduce their number. This preoccupation with the negative was recognised by Professor James Reason, who in 2020 wrote about the paradoxes of safety and pointed out that hat safety is defined and measured more by its absence than its presence. The efforts to reduce the number of unexpected and unacceptable outcomes signify a decremental approach to safety, where the completely aim is to have zero unexpected and unacceptable outcomes. Since safety is measured by the number of unexpected and unacceptable outcomes, the result is a relation where the magnitude of the output is inversely related to the magnitude of the input. The efforts spent to further decremental safety are therefore a cost, which at best may save the losses incurred by a major unexpected and unacceptable outcome. The ultimate goal of having no unexpected and unacceptable outcomes at all is, however completely unattainable due to the inevitable unpredictability of processes and conditions that follow from the law of entropy. There is, fortunately, a sensible logical alternative to decremental safety and the fruitless efforts to increase the absence of safety, namely to adopt a positive stance and instead increase the presence of safety, i.e., to try to have as many expected and acceptable outcomes as possible. This corresponds to a 180 degrees change of course Since safety in this way measured by the number of expected and acceptable outcomes, the relation is one where the magnitude of the output is directly related to the magnitude of the input. The efforts spent to further decremental safety are therefore an investment. he ultimate goal of having only expected and acceptable outcomes is also completely unattainable due to the inevitable unpredictability of processes and conditions that follow from the law of entropy.
But it is less of a calamity because each step serves to increase the number of expected and acceptable outcomes. This is an incremental approach to safety that obviously makes good business sense and in the end leads to a reduction of the number of unexpected and unacceptable outcomes, simply because an outcome can neither be both expected and unexpected at the same time nor both acceptable and unacceptable. Expected and acceptable outcomes characterise work that goes well , but unlike the negative outcomes the current safety legacy has neither methodology nor terminology to support this aim.
Incremental safety tries to increase the presence of safety instead of increasing the absence of safety, with the ultimate goal that there only are expected and acceptable outcomes. This is, of course, as unrealistic as the goal of decremental safety and for the very same reasons. But whereas decremental safety and the pursuit of the Zero Accident Vision represent a cost. Incremental safety and the pursuit of the corresponding visio centum represents an investment. It will in the end not only reduce the number of unexpected and unacceptable outcomes but also lead to more expected and acceptable outcomes on the way. Choosing incremental safety over decremental safety is therefore an obvious nobrainer.
The full text of the Incremental Safety Manifesto is here